science news 22.1.2019

Today's round-up of science stories. Links are normally to press releases on EurekAlert (at the bottom end I may also add a couple of newspaper stories). I include quotes from the summary (using quotation marks) in cases where the title alone doesn't reveal what the story is about.


evolution

Fossilized slime of 100-million-year-old hagfish shakes up vertebrate family tree

Ancient carpet shark discovered with 'spaceship-shaped' teeth
"The world of the dinosaurs just got a bit more bizarre with a newly discovered species of freshwater shark whose tiny teeth resemble the alien ships from the popular 1980s video game Galaga."



Galagadon
Credit: (c) Velizar Simeonovski, Field Museum


climate change

Greenland ice melting four times faster than in 2003, study finds


nanoworld

Broadband achromatic metalens focuses light regardless of polarization



humans

The diversity of rural African populations extends to their microbiomes

Study: On Facebook and Twitter your privacy is at risk -- even if you don't have an account


--------------

from the news media

"If all of Greenland’s vast ice sheet, 3km thick in places, was to melt, global sea levels would rise by seven meters," writes the Guardian, in a piece about faster than expected ice loss in Greenland (see the press release for the PNAS paper above, under climate change). Note,however, that melting isn't even necessary for this catastrophic sea level rise to happen. If the ice were to slide off the landmass and float around in the Atlantic, it would cause exactly the same effect, as it displaces its own weight in liquid water.